Long-term Clinical Outcome and Echocardiographic Restenosis after Successful Percutaneous Transmitral Commissurotomy

ABSTRACT

BACKGROUND: The purpose of this study was to assess the clinical outcome and echocardiographic incidence of restenosis after successful percutaneous transmitral commissurotomy (PTMC) and to identify predictors of restenosis. METHODS: Between 1989 and 1992, Inoue PTM (n=73) and double balloon technique (n=85) were used in 158 consecutive patients (male 52, age; 41+/-11 year) with mitral stenosis. Clinical and echocardiographic examinations were performed annually in 137 patients who exhibited good initial result with PTMC (mitral valve area 1.5cm (2) and mitral regurgitation[MR] 2+). Restenosis was defined as a mitral valve area< (MVA) 1.5cm (2) or more than 50% loss of the initial gain in MVA. Commissural mitral regurgitation (CMR) was defined as MR originating from medical or lateral commissure on color flow imaging and regarded as an index of complete commissural splitting. RESULTS: Immediately after PTMC, MVA increased from 0.9+/-0.2cm (2) to 1.8+/-0.3cm (2) and functional class improved up to NYHA class 1 or 2 in all patients. Annual echocardiographic follow-ups were completed in 129 (94%) patients and mean follow-up duration was 54+/-21 months. Adverse events occurred in 16 (13%) patients (1 death, 3 mitral valve replacement, 3 re-PTMCs, 9 deterioration of the NYHA class), and restenosis occurred in 41 (32%) patients. Event-free and restenosis-free survival rates at 7 years were 776 % and 586 %, respectively. According to multivariate Cox analysis, restenosis (p=0.0017, relative risk[r.r]=2.82) was the only predictor of adverse events ; smaller increase ( 1.0cm (2)) of MVA (p=0.0001, r.r=4.8) and the absence of CMR (p=0.0000, r.r=4.8) were independent predictors of restenosis. CONCLUSION: Long-term clinical outcomes and restenosis rates after PTMC are favorable and immediate results after PTMC can predict late restenosis better than baseline clinical and echocardiographic characteristics.